The present invention relates to a capacitor module and, more particularly, to a capacitor module in which a plurality of capacitors, forming a capacitor module, are disposed in proximity to each other.
In recent years, a hybrid vehicle provided with a drive-force source composed of an engine, such as an internal combustion engine, and a motor such as an electric motor, have been widely spread in use. Such a hybrid vehicle has a power drive unit through which a direct current, supplied from a battery, is converted to an alternate current for supply to the motor whereas an alternate current, resulting from regenerative operation of the motor, is converted to a direct current for storage in the battery.
The power drive unit typically includes a capacitor module for smoothing the direct current delivered from the battery, and a power module for converting the direct current, smoothed by the capacitor module, into the alternate current. With such a power drive unit, since a need has been arisen to have a capacitor module with further increased capacity, it has been proposed to form a capacitor module with a plurality of capacitors for thereby increasing a capacity of the capacitor module.
Japanese Patent Application Laid-Open Publication No. H5-207746 discloses a structure, related to an inverter, in which capacitor units, composed of a group of smoothing capacitors, which are accommodated one above the other in a case in multiple stages. Two positive electrode bus bars and one negative electrode bus bar are arranged to stand upright at backsides of the capacitor units such that the positive electrode terminals of the capacitor units are directly connected to one of the two positive electrode bus bars and the negative electrode terminals of the capacitor units are directly connected to the negative electrode bus bar.
Japanese Patent Application Laid-Open Publication No. 2001-245480 relates to a semiconductor power conversion device including eight pieces of capacitors, disposed in two rows, having terminals which are placed in two rows on the same plane, respectively. In particular, one pieces of the terminals of the capacitors are connected to an intermediate conductor, with the other pieces of the terminals of the capacitors are correspondingly connected to a positive electrode conductor and a negative electrode conductor. Such three conductors are stacked in electrically insulated condition from each other.